Key operated switch arrangement



Feb. l, 1966 o. WINTER E'rAL 3,233,070

KEY OPERATED swITcH ARRANGEMENT Filed Nov. 6, 1963 2 Sheets-Sheei'I 1 Feb. 1, 1966 o. WINTER ETA'. 3,233,070

KEY OPERATED SWITCH ARRANGEMENT Filed Nov. 6, 1963 2 Sheets-Sheet 2 /N VE N TOPS United States Patent 3,233,070 KEY OPERA'EED SWITCH ARRANGEMENT Otto Winter and Hans Eichemeyer, Wilhelmshaven, and Reif Koenen, Wuppertal-Barmen, Germany, assignors to Olympia Werke AG., Wilhelmshaven, Germany Filed Nov. 6, 1963, Ser. No. 321,943 Claims priority, application Germany, Nov. 7, 1962, 9,060 15 Claims. (Cl. 200-159) The present invention relates to a key operated switch arrangement, and more particularly to apparatus, such as electric typewriters or calculators, in which rows of keys are arranged to operate switches.

It is one object of the present invention to improve key operated switches, particularly of the type used in typewriters and calculators, and to provide a key operated switch of simple mechanical construction which can be economically manufactured and easily assembled.

Another object of the invention is to provide simple and effective means for limiting the movement of the key in contact closing and contact opening positions.

Another object of the invention is to mount a key operated switch in a very simple manner on a mounting plate.

Another object of the invention is to provide -a particularly simple way of mounting a bridging contact on the key so that the bridging contact can be moved to and from a position connecting two fixed contacts.

Another object of the invention is to provide a key operated switch arrangement in which conductive parts are separated from adjacent switches by insulating material.

With these objects in View, the present invention relates to a key operated switch arrangement which is particularly suited for typewriters and calculators in which rows of key operated switches are provided.

One embodiment of the invention comprises a mounting plate having a first guide opening; an insulating support plate secured to the mounting plate spaced from the same and having a second guide opening aligned with the first guide opening; a pair of fixed contacts secured to the support plate; a key mounted in the guide openings and preferably having a pair of abutments consisting of an insulating material; and a contact spring mounted between the abutments of the key for movement with the same to and from a position abutting the fixed contacts and connecting the same.

In the preferred embodiment of the invention, the support plate is a part of a U-shaped insulating body whose legs are secured to the mounting plate, preferably by a pair of tongues passing through corresponding slots in the mounting plate, and being held by a holding spring passing through openings in the tongues. In the preferred embodiment of the invention, t-he key has a stem provided with an elongated slot through which the holding spring passes to limit the movement of the key in two end positions.

A return spring abuts the key stem and the support plate and urges the key to move to the normal inoperative position in which one end of the slot abuts the holding spring. When the key is depressed, the return spring is compressed until the contact spring engages the two fixed contacts, and at the same time, the other end of the slot in the key stem engages the holding spring, and slightiy deforms the same until the key is blocked.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a front view, partially in section, of a key operated switch arrangement according to the invention;

FIG. 2 is a side view, partly in section of the key operated switch arrangement shown in FIG. l;

FIG. 3 is an exploded perspective view illustrating the key operated switch; `and FIG. 4 is a fragmentary plan View, partially in section and broken off, illustrating a key operated switch arrangement according to the invention.

Referring now to the drawings, a U-shaped insulating body 1 includes two legs in the form of rectangular plates 1, and a connecting support plate 4 which is also of rectangular configuration so that the insulating body 1 is substantially prismatic. A pair of fixed contacts 9 with connecting portions 9' adapted to be soldered to a conductor, are secured to support pl-ate 4, and are preferably attached to the insulating body when the same is injection molded.

Each leg of the insulating body 1 has a tongue 2 with a hole or slot 2. Tongues 2 are parallel to each other and inclined to the plane of symmetry of the U-shaped insulating body 1, as best seen in FIG. 3.

As shown in FIG. 4, the tongues 2 are inserted into corresponding slots 13 in a mounting plate 13, and as best seen in FIG. 1, a holding spring 14 is inserted through the aligned holes or slots 2' and has end portions 14 resiliently engaging the ends of slots 2 so that the curved end portions 14 of spring 14 abut the mounting plate and securely hold the U-shaped insulating body 1 attached to the mounting plate. The center portion of spring 14 is arcuate and spaced from the top surface of the mounting plate.

A key includes a button 15 and a key stem 6 which passes through a guide opening 13 in mounting plate 13, and through another guide opening 5 in the support plate 4 so that the key is guided for movement in vertical direction. The key stem 6 has an elongated slot 6", as best seen in FIGS. 2 and 3, and the central arcuate portion of holding spring 14 passes through slot 6, normally abutting the lower end of slot 6 since a return spring S abuts a recess 7 in support plate 4 and an insulating piece 10 secured to key stem 6 to urge the key to the upper normal position illustrated in FIGS. l and 2.

However, when the key is depressed, coil spring 8 is compressed until the upper end of slot 6" engages the central portion of spring 14. The key is not completely blocked in this position, but can move further until the arcuate portion of holding spring 14 is completely fiattened and abuts the top surface of mounting plate 13.

The insulating piece 10 has a central prismatic portion surrounding the key stem, a portion 10a, see FIG. l, passing through a hole in stem 6, a pair of substantially saddle-shaped abutments 10', and a pair of downwardly depending portions 10 abutting the sides of stern 6. Stem 6 and insulating piece 10 are integral, since the insulating piece 10 is injection molded onto stem 6.

An insulating abutment, namely the pin shaped insulating abutment 12, see FIGS. l and 2 passes through portion 10a of the insulating piece 10 and projects 011 opposite sides from the same so as to form gaps with the saddle-shaped insulating abutments 10', Abutment pin 1.2 may be a slotted tubular member.

A contact spring 11 of M-shaped configuration is mounted on insulating piece 10. The shape of contact spring 11 is best seen in FIG. 3, and it will be seen that this spring has two legs 11" inclined to each other, and a recessed connecting portion. A longitudinal slot 11 is provided in parts of the legs 11" and in connecting portion.

Contact spring 11 is seated on insulating piece 1) with stem 6 passing through slot 11', and with the free ends of abutment pin 12, namely of the pin shaped insulating abutment located in the recessed connecting portions of spring `111. The inner surfaces of the connecting portions respectively abut the top faces of the saddle-shaped insulating abutments 10', while the ends of the abutments T10 engage the inner surfaces of legs 11, as best seen in FG. 2.

The assembly is carried out by removing button 15, placing the contact spring 11 on stem 6 and insulating piece 10, and then inserting the abutment pin 12, whereupon the button is secured to stem 6.

In this manner, contact spring .11 is securely attached to the key for movement with the same between the illustrated inoperative position and a position in which the key is depressed and the confronting inner surfaces of leg `11i of contact spring 11 abut the fixed contacts 9 in a slightly spread position to connect lthe same. A slight pivotal swivel movement of contact spring 11 about pin 12 is possible so that a satisfactory engagement between the legs of the contact spring 11 and the fixed contacts 9 is assured.

In the normal illustrated position of the key operated switch, coil spring 8 holds stem 6 in a position in which the lower edge of slot 6" engages holding spring 14 While contact spring 11 is spaced from contacts 9. When the key is depressed, contact spring 11 moves toward contacts 9, and when the same are engaged, the vupper edge of slot 6 engages the highest point of the arcuate central portion of holding spring 14 vand depresses the same so that the legs 1i of contact spring 11 are also resiliently deformed and a suitable kcontact pressure is produced. When the arcuate portion of holding spring 14 is completely flattened and abuts mounting plate 13, the key cannot be moved further so that extreme deformation of the contact spring is avoided. Upon release of the key, springs 14 and 8 willcooperate to rapidly break the contact between contact spring 11 and contacts 9. While spring 14 is adapted to completely block movement of the key, it resiliently overcomes the finger pressure exerted on the key so that fatigue of the operator is avoided.

`When contact spring 11 fully abuts contacts 9, it is slightly raised and lifted off the saddle-shaped abutments 16'. When spring 8 returns the key to its completely retracted normal position, the lower edge of slot 6 engages the center portion of holding spring 14, so that the `upward movement of the key under the action of coil spring 8 is dampened.

As best seen in FIG. 4, the inclined position of slots 13 in the mounting plate, and of tongues 2 relative to the leg plates of the U-shaped insulating body 1, results in an oblique position of holding spring 14, so that the holding springs of adjacent key operated switches do not interfere with each other, while the U-shaped prismatie insulating bodies are arranged with the sides thereof parallel to each other.

FIG. 4 illustrates by way of example two rows of pairs of openings 13 and `openings 13 in the mounting plate 13, corresponding to two rows of key operated switches. The openings 13 are staggered to each other, corresponding to a staggered arrangement of the keys of the two rows. As best seen in FIG. 2, the mounting plate 13 has a vertical shoulder 13a separating adjacent rows of keys. However, an inclined mounting plate 13b may be substituted for the stepped mounting plate i3, and such a construction is illustrated in phantom lines in FlG. 2. The angle of the inclined mounting plate 13b is determined in accordance with the German standard construction DIN 2127, and corresponds substantially to an angle of 15, or to a ratio of 5: 19.

It will be understood that each 4of the elements described above, or two or more together, may also find a useful application in other types of key operated switch arrangement differing from the types described above.

While the invention has been illustrated and described as embodied in a key operated switch including a contact spring mounted between two abutments on the key, it is notintended to be limited to the details shown, since various modifications and structu-ral changes may be made without departing in any way from the spirit of the present invention.

`Vithout further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A key operated switch arrangement comprising, in combination, a mounting plate having a first guide opening and a pair of slots on opposite sides of said first guide opening; a U-shaped insulating body having a pair of legs and a support plate connecting said legs and having a second guide opening aligned with said first guide opening; a pair of tongues secured to the ends of said legs and passing through said slots o-f said mounting plate, said tongues having opposite openings; a holding member passing through said openings and abutting said mounting plate for securing said body to said mounting plate; a pair of fixed contacts secured to said support plate; a key mounted in said guide openings for movement in one direction; and a contact spring mounted on vsaid key for movement in said direction to and from a position abutting said contacts and connecting the same.

2. A key operated switch arrangement comprising, in combination, a mounting means; an insulating support secured to said mounting means; a pair of 'fixed contacts secured to said support; a key movably mounted on said support and having a pair o-f .spaced insulating abutments; and a contact spring having two legs and a connecting portion pivotally mounted on said key between said abutments for movement with said .key to and from a position abutting said contacts in a pivotally adjusted position in which said legs fully abut both said fixed contacts.

3. A key operated switch arrangement comprising, in combination, a mounting plate having a rst guide opening; an insulating support plate secured to said mounting plate spaced from the same, said support plate having a second guide opening aligned with said first guide opening; a pair of fixed contacts secured to said support plate; a key mounted in said guide openings for movement in ,one direction, said key having a pair of spaced insulating abutments; and a contact spring mounted on said key for movement in said direction to and from a position abutting said contacts and connecting the same, said contact spring including a pair of legs extending at an acute angle to each other and having ends located opposite said contacts, and a connecting portion connecting said legs and located between said abutments and supported by the same for pivotal movement about an axis transverse to said one direction so that said contact spring turns about said axis until both leg ends fully abut said fixed contacts.

4. A key Aoperated switch arrangement comprising, in combination, a mounting plate having a first guide opening; an insulating support plate secured to said mounting plate spaced from the same, said support plate having a second guide opening aligned with said first `guide opening; a pair of fixed contacts secured to said support plate; a key mounted in said guide openings for movement in one direction, said key having a pair of spaced insulating labutments, one of said abutments being a pin and the other abutment being substantially saddle-shaped; and an M-shaped contact spring mounted on said key for movement in said direction to and from a position abutting said contacts and connecting the same, said contact spring including a pair of legs extending at an acute angle to each other and having ends located opposite said contacts, and a connecting portion formed with a bearing recess, connecting said legs and located between said abutments, said pin being located in said bear-ing recess of said connecting portion and said saddle-shaped abutment having portions abutting said legs so that said contact spring is supported on said pin for pivotal move- 'ment and turns about the same until said leg ends fully abut said ixed contacts.

5. A key operated switch arrangement comprising, in combination, a mounting plate having a rst guide opening; a U-shaped insulating body having a pair of legs and a support plate connecting said legs and having a second guide opening aligned with said tirst guide opening; means at the ends of said legs for securing said vvbody to said mounting plate; a pair of fixed contacts secured to said support plate; a key mounted in said guide openings for movement in one direction, said key having a pair of spaced insulating abutments; and a contact spring mounted on said key for movement in said direction to and from a position abutting said contacts and connecting the same, said contact spring including a pair of outwardly spreading legs having confront-ing inner surfaces located opposite said contacts, and a connecting portion connecting said legs and located between said abutments and supported by the same for pivotal movement about an axis transverse to said one direction so that said con-tact spring Iturns about said axis until both said inner surfaces fully abut said .t fixed contacts.

6. A key ope-rated switch arrangement comprising,

yin combination, a mounting plate having a irst guide opening and a pair of slots on opposite sides of said first guide opening; a U-shaped insulating body having a pair of legs and 4a support plate connecting sa-id legs and having a second guide opening aligned with said first guide opening; a pair of tongues secured to the ends of said legs and passing through said slots of said mounting plate, said tongues having opposite openings; a hold-ing member passing through said openings and abutting said mounting plate for securing said body to said mounting plate; a pair of iixed contacts secured to said support plate; a key mounted in said guide openings for movement in one direction, said key having a pair of spaced insulating abutments, one of said abutments being a pin and the other abutment being substantially saddle-shaped; and an M-shaped contact spring mounted on said key for movement in said direction to and from a position abutting said contacts and connecting the same, said contact spring including a pair of legs having ends located opposite said contacts, and a U-shaped connecting portion connect-ing said legs and located between said abutments, said pin being located in said U-shaped connecting portion and said saddle-shaped abutment having portions abutting said legs.

7. A key operated switch arrangement comprising, in combination, a mounting plate having a tirs-t guide opening and a pair of slots on opposite sides of said first guide opening; a U-shaped insulating body having a pair of leg plates and a support plate connecting said leg plates and formed with a second guide opening aligned with said first guide opening; a pair of tongues having holes secured to the ends of said leg pla-tes and passing through said slots in said mounting plate; a pair of fixed contacts secured to said support plate; a key mounted in said guide openings for movement between first and second positions and having a stem formed with a slot aligned with said holes outside of said mounting plate; a holding spring passing through said holes and said slot of said key abutting said mounting plate for attaching said insulating body and for limiting movement of said key in said positions; a Contact spring mounted on said key for movement therewith to and from a connecting position abutting said contacts and connecting the same While said key is in said second position and one end of said slot therein abuts said holding spring; and a return spring abutting said key and said support plate for urging said key to said first position in which said contact spring is spaced from said contactsand other end of said slot in said key abuts said holding spring.

8. A key operated switch arrangement comprising, in combination, a mounting plate having a first guide opening and a pair of slots on opposite sides of said first guide opening; a U-shaped insulating body having a pair of leg plates and a support plate connecting said leg plates and formed with a second guide opening aligned with said iirst guide opening; a pair of tongues having holes secured to lthe ends of said leg plates and passing through said slots in said mounting plate; a pair of fixed contacts secured to said support plate; a key mounted in said guide openings for movemen-t between first and second positions and having a stem formed with a slot aligned with said holes outside of said mounting plate; a holding spring passing through said holes and said slot of said key abutting said mounting plate .for attaching said insulating body and for limiting movement of said key in said positions, said holding spring having an arcuate center portion passing through said slot in said key and a pair of bent arms located in said holes of said tongues; a contact spring mounted on said key for movement therewith to and from a connecting position abutting said contacts and connecting the same While said key is in said second position and one end of said slot therein abuts said holding spring; and a return spring abutting said key and said support plate for urging said key to said iirst position in which said contact spring is spaced from said contacts and other end of said slot in said key abuts said holding spring.

9. A key operated switch arrangement comprising, in combination, la mounting plate having a iirst guide opening and a pair of slots on opposite sides of said rst 'guide opening; a U-shaped insulating body having a pair of leg plates and a support plate connec-ting said leg plates and formed with a second guide opening aligned with said tirst guide opening; a pair of tongues having holes secured to the ends of said leg plates and passing through said slots in said mounting plate; a pair of fixed contacts secured to said support plate; a key mounted in said guide openings for movement between lirst and -second positions and having a stem formed with a slot aligned with said holes outside of said mounting plate; a holding spring passing through said holes and said slot of said key abutting said mounting plate for attaching said insulating body and for limiting movement of said key in said positions, said key having a pair of spaced insulating abutments; a contact spring mounted on said key between said abutments for movement therewith to and from a connecting position abutting said contacts and connecting the same while said key is in said second position 1and one end -of said slot therein abuts said holding spring; and a return spring abutting said key and said support plate for urging said key to said first position in which said contact spring is spaced from said contacts and other end of said slot in said key abuts said holding spring.

10. A key oper-ated switch arrangement comprising as set forth in claim 9 wherein said contact spring has a pair of legs having ends located opposite said contacts and a recessed connecting portion connecting said legs and located between said abutments, one of said abutments being located between said legs and having por-tions abutting the same and the other abutment being a pin located in said recessed connecting portion so that said contact spring is pivotally supported on said pin.

11. A key operated switch arrangement comprising, in

combination, a mounting plate; an insulating support secured to said mounting plate; a pair vof xed contacts 'secured to said support; a key movably mounted on said support and having a slot; a limiting spring passing through said slot and blocking movement of said key in irst and second positions in which the ends of said slot abut said limiting spring; a return spring abut-ting said support and said key for urging the same to said first position; and a contact spring mounted on said key for movement in said direction to and from aposition abutting said cont-acts and connecting the same while said key is in said second position and said return spring is compressed.

112. A key operated switch arrangement comprising, in combination, a mounting plate having a rst guide opening; an insulating support plate secured to said mounting plate spaced from the same, said support plate having a second guide opening aligned with said first guide opening; a pai-r of lixed contacts secured to said support plate; a key mounted in said guide openings for movement in one direction, said key having a slot; .an arcuate limiting spring passing through saidV slot and lblocking movement of said key in first and second positions `in which the ends of Said slot abut said limiting spring; a return spring abutting said support plate and said key for urging the same to said rst position; and a contact spring mounted on said key for movement sin said direction toand from a position abutting said contacts and connecting the same While said key is in said second position and said return spring is compressed While said arcuate spring is deformed and flattened to abut said mounting plate.

i3. An arrangement as set forth in claim 9 wherein said fixed contacts are cast into said support plate between said leg plates; wherein said stem is cast into said insulating body and has an opening through which a portion of said insulating body passes; and wherein one of said abutment-s is a pin passing through said portion of said body.

i4. A key operated switch arrangement, comprising, in combination, a mounting means; support means secured to said mounting means; a pair of fixed contacts secured to said support means; a key mounted on said mounting means for movement in one direction; and a contact spring having a central connecting portion .mounted on said key for movement therewith in said direction, and for pivotal movement about an axis transverse to said direction, said contact spring -having at the ends of said connecting portion a pair .of outwardly spreadng legs slanted to each other and to said connecting portion and having confronting inner contact aces extending transversely to said one direction, said contact spring being movable with said key to a posltion in which said contact faces abut said fixed contacts while said legs are resiliently spread by said iixed contacts.

15. A key operated switch arrangement, comprising, in combination, a mounting means; support means secured to said mounting means; a pair of xed contacts secured to said support means; a key mounted on said mounting means for movement in one direction and having an insulated pin; and an M-shaped .contact spring having a recessed central connectngportion mounted on said key for movement therewith in said direction with said recessed connecting portion .turnably engaging said pin so that saidcontact sprlng is mounted onsaid key for pivotal movement about an axis transverse to said direction, Said contact spring having at the 4ends of said connecting portion a pair of outwardly spreading legs slanted to each other and to said connecting portion and having confronting inner contact faces extending transversely to said one direction, said contact spring being movable with said key to a position in which said contact faces abut said fixed contacts while said legs are resiliently spread by said tixed contacts.

References Citedby the Examiner UNITED STATES PATENTS 460,458 4/1891 Gruschow 20o-159 1,859,981 5/1932 Norviei 20o-159 2,567,421 9/1951 Bramingson 20o-159 3,038,053 6/1962 Long et al. ZOO-159 ROBERT S, MACON, Acting Primary Examiner.

ROBERT K. SCHAEFER, KATHLEEN H. CLAFFY, Examiners.

w. Cl GARVERT, Assistant Examiner. 

1. A KEY OPERATED SWITCH ARRANGEMENT COMPRISING, IN COMBINATION, A MOUNTING PLATE HAVING FIRST GUIDE OPENING AND A PAIR OF SLOTS ON OPPOSITE SIDES OF SAID FIRST GUIDE OPENING: A U-SAHPED INSULATING BODY HAVING A PAIR OF LEGS AND A SUPPORT PLATE CONNECTING SAID LEGS AND HAVING A SECOND GUIDE OPENING ALIGNED WITH SAID FIRST GUIDE OPENING; A PAIR OF TONGUES SECURED TO THE ENDS OF SAID LEGS AND PASSING THROUGH SAID SLOTS OF SAID MOUNTING PLATE, SAID TONGUES HAVING OPPOSITE OPENINGS; A HOLDING MEMBER PASSING THROUGH SAID OPENINGS AND ABUTTING SAID MOUNTING PLATE FOR SECURING SAID BODY TO SAID MOUNTING PLATE; A PAIR OF FIXED CONTACTS SECURED TO SAID SUPPORT PLATE; A KEY MOUNTED IN SAID GUIDE OPENINGS FOR MOVEMENT IN ONE DIRECTION; AND A CONTACT SPRING MOUNTED ON SAID KEY FOR MOVEMENT IN SAID DIRECTION TO AND FROM A POSITION ABUTTING SAID CONTACTS AND CONNECTING THE SAME. 